Human H5N1 IgG ELISA kit measures IgG antibody is serum or plasma samples. The kit employs purified recombinant H5N1 protein to specifically detect antibodies to influenza subtype H5N1. The kit is particularly suited to assess the H5N1 antibody levels in vaccinated and non-vaccinated samples or to determine the efficacy of new vaccines or formations. For research use only (RUO), not for diagnosis, cure or prevention of the disease.